BOTANY. 



during the winter. After flowering and 

 leafing their herbage and fibres decay, and 

 the roots may then be removed or kept 

 out of the ground for a time without any 

 hazard. When fresh fibres are formed it 

 is fatal to disturb them. 



7th. A granulated Yoo^granulata, agrees 

 in physiology with the last, being a clus- 

 ter of little bulbs or scales connected by a 

 common fibre, as in the white saxifrage 

 and wood sorrel. Fig. 7. 



Buds of trees have a great anakgy with 

 the bulbs and knobs of the roots in her. 

 baceous plants. In them the vital prin- 

 ciple is latent till a proper season for its 

 evolution arrives. For this reason buds 

 are essential to the trees or shrubs of cold 

 countries, and are formed in the course 

 of the summer in the bosoms of their 

 leaves. The plane-tree has them conceal- 

 ed in the base of its foot-stalk, which 

 answers the purpose of protection. In 

 most instances they are guarded by scales, 

 furnished with gum or woolliness, as an 

 additional defence. Till buds begin to 

 vegetate, they very powerfully resist cold, 

 and are scarcely known to suffer at any 

 season ; but it is quite otherwise when 

 they have made ever so slight an effort to 

 develope themselves. Plants are propa- 

 gated by* buds as commodiously as by 

 roots. Those of. one tree may be engraft- 

 ed on the bark of another of the same 

 species, or one nearly akin, by which, as 

 is well known, valuable varieties are mul- 

 tiplied. Fig. 8. 



It is remarkable, that nature should per- 

 mit such devastation and waste as is made 

 by many insects, whose caterpillars or 

 grubs feed on the buds of trees. Several 

 species of fir are infested with their ap- 

 propriate insects, which, literally speak- 

 ing, devour their vitals, and should seem 

 to be capable in one season of destroying 

 a whole forest. Yet these are only in- 

 struments in the hand of Providence, 

 which, like many others, though formida- 

 ble in appearance, are never allowed to 

 transgress their due bounds. 



OF THE STEMS AND STALKS OF PLANTS. 



Botanists reckon seven kinds of stems 

 or stalks of plants. 



1. Caulis, a stem, fig. 9. properly so call- 

 ed, bears both leaves and flowers, as the 

 trunks and branches of all trees and 

 shrubs, as well as of many herbaceous 

 plants besides. By its means the organs 

 of plants are raised lo a commodious 

 height above the ground, and presented 



in various directions to the atmosphere 

 and light. In germination, it always takes 

 a contrary direction to the root. As it 

 advances in growth, it is either able to 

 support itself, or twines round or ad- 

 heres to other bodies. Some stems creep 

 on the ground, and take root here and 

 there, by which the plant is increased. 

 The stem is either simple, as in the lily, 

 or branched, as in the generality of plants. 

 When regularly and repeatedly divided, 

 with a flower springing from each divi- 

 sion, it is called caulis dichotomus, a fork- 

 ed stem. Though generally leafy or 

 scaly, a stem may be naked in plants 

 destitute of leaves altogether, as the 

 creeping cereus, and the genus staphe- 

 lia. Climbing stems are of several kinds ; 

 as radicans, clinging to any other body 

 for support, by means of fibres which do 

 not imbibe nourishment; scandens, climb- 

 ing by means of spiral tendrils, like the 

 vine and passion-flower; volubilis, twin- 

 ing round any thing that comes in its 

 way by its own spiral form, either from 

 left to right, according to the apparent 

 motion of the sun, like the honeysuckle, 

 or from right to left, like the convolvo- 

 lus and French bean ; nor can any art or 

 force make a twining stem turn contrary 

 to its natural direction. In the manner 

 of their growth and branching stems are 

 very various, being either straight, irre- 

 gularly spreading, or zigzag : either al- 

 ternately branched or oppositely ; two- 

 ranked, when the branches spread in two 

 horizontal directions; or brachiate, four- 

 ranked, when they spread in four direc- 

 tions, crossing each other alternately in 

 pairs. Caulis determinate ramosus t an ab- 

 ruptly branched stem, belongs particu- 

 larly to the heaths, the rhododendron, 

 &c. and is a term invented by Linnxus to 

 express their peculiar mode of growth ; 

 each of their branches, after terminating 

 in flowers, throws out a number of fresh 

 ascending shoots from just below the 

 flowering part. The Indian fig has a re- 

 markable jointed stem, whose ovate por- 

 tions look like leaves ; possibly the scales 

 with which they are covered may be 

 equivalent to leaves. 



The shape of a stem is either round 

 or two-edged, as in the everlasting pea, 

 or with three, four, or more angles. 

 Square stems are extremely common, 

 and such generally bear opposite leaves. 

 Several stems are winged, the angles 

 being extended into leafy borders, as in 

 thistles. 



The surface of the stem is either 

 smooth, rough, watery, viscid, bristly, 

 hairy, downy, woolly, hoary, or glaucous 



